TARGETED RIBOZYMES REVEAL A CONSERVED FUNCTION OF THE DROSOPHILA PAIRED GENE IN SENSORY ORGAN DEVELOPMENT

The Drosophila paired (prd) gene, the founding member of the PAX gene family, is required for normal embryonic segmentation and is re-expres sed later in development in the head and developing CNS. As for most e mbryonically active genes, global defects resulting from loss of early prd function obscure an analysis of the role of later expression phas es. We used heat inducible targeted ribozymes to functionally 'knock-o ut' prd at late stages. When prd protein levels in the head are reduce d in this fashion, the maxillary chemosensory ventral organs fail to d evelop and dorsal-lateral cirri rows are disrupted. These studies reve al a role for prd in sensory organ development that appears to be cons erved in PAX genes throughout the animal kingdom.